U.S. patent number 5,011,560 [Application Number 07/234,159] was granted by the patent office on 1991-04-30 for method of adhesion and composition therefor.
This patent grant is currently assigned to Takeda Chemical Industries, Ltd.. Invention is credited to Tsutomu Kubota, Yoshikazu Nakai.
United States Patent |
5,011,560 |
Nakai , et al. |
April 30, 1991 |
Method of adhesion and composition therefor
Abstract
A method of adhesion which comprises applying a two-step
reactive type tacky adhesive agent comprising (1) a
non-photopolymerizable epoxy resin or isocyanate compound, (2) a
curing agent therefor and (3) a compound having at least one
photopolymerizable vinyl group in one molecule onto a substrate,
irradiating the whole applied surface with light to develop the
tackiness, and sticking the substrate together to a material to be
bonded, while the tackiness is retained, followed by curing. The
method provides excellent green bonding strength and can permit the
satisfactory adhesion without clamping, and can be particularly
suitably utilized in the adhesion of materials to be bonded which
have a curved surface difficult to be clumped.
Inventors: |
Nakai; Yoshikazu (Itami,
JP), Kubota; Tsutomu (Mishima, JP) |
Assignee: |
Takeda Chemical Industries,
Ltd. (Osaka, JP)
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Family
ID: |
27275080 |
Appl.
No.: |
07/234,159 |
Filed: |
August 19, 1988 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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928656 |
Nov 5, 1986 |
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700673 |
Feb 11, 1985 |
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Foreign Application Priority Data
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Feb 13, 1984 [JP] |
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59-25691 |
Apr 5, 1984 [JP] |
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59-68636 |
Jan 8, 1985 [JP] |
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60-1800 |
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Current U.S.
Class: |
156/273.3;
156/331.4; 428/414; 428/416; 428/423.7; 428/424.4; 428/425.1;
428/425.3; 428/425.8; 428/463; 522/101; 522/103; 522/126; 522/14;
522/174; 522/28; 522/96 |
Current CPC
Class: |
C08G
18/637 (20130101); C09J 5/00 (20130101); C09J
163/00 (20130101); C09J 175/04 (20130101); C09J
175/16 (20130101); Y10T 428/31522 (20150401); Y10T
428/31576 (20150401); Y10T 428/31699 (20150401); Y10T
428/31515 (20150401); Y10T 428/31565 (20150401); Y10T
428/31591 (20150401); Y10T 428/31605 (20150401); Y10T
428/31594 (20150401) |
Current International
Class: |
C09J
163/00 (20060101); C09J 175/14 (20060101); C09J
175/16 (20060101); C08G 18/00 (20060101); C08G
18/63 (20060101); C09J 175/04 (20060101); C09J
5/00 (20060101); B32B 001/10 (); B32B 031/12 ();
C08G 018/42 (); C08G 018/58 () |
Field of
Search: |
;156/273.3,330 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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48-21800 |
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Mar 1973 |
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JP |
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52-8043 |
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Jan 1977 |
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JP |
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58-149971 |
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Sep 1983 |
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JP |
|
Other References
Noomen, "Pigmented UV Dual Cure Coatings"..
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Primary Examiner: McCamish; Marion E.
Assistant Examiner: Koeckert; Arthur H.
Attorney, Agent or Firm: Wenderoth, Lind & Ponack
Parent Case Text
This application is a continuation of now abandoned application
Ser. No. 928,656 filed Nov. 5, 1986, now abandoned, which is a
continuation of application Ser. No. 700,673 filed Feb. 11, 1985,
now abandoned.
Claims
We claim:
1. A method of adhesion which comprises (a) applying onto a
substrate having a curved surface a liquid two-step reactive type
tacky adhesive agent comprising (1) a non-solvent or high-solid
isocyanate compound, (2) a curing agent therefor and (3) a
component consisting of a vinyl compound having one
photopolymerizable vinyl group per molecule and a vinyl compound
having at least two photopolymerizable vinyl groups per molecule,
the weight of the former vinyl compound being in the range of 30 to
100 weight % of component (3) and the porportion of component (3)
being about 5 to 80 weight % of the total amount of the tacky
adhesive agent, (b) irradiating the whole applied surface with
light to develop tackiness at a glass transition temperature of the
applied agent after irradiating with light not exceeding about
20.degree. C., and (c) adhering the substrate to a material to be
bonded to the said curved surface through the said adhesive agent
without clamping, while the tackiness is retained, followed by
curing at room temperature.
2. A method of adhesion as claimed in claim 1, wherein the
component (1) is an isocyanate compound and the component (2) is an
acrylic polyol.
3. A method of adhesion as claimed in claim 1, wherein the
component (3) is one selected from the group consisting of
poly(meth)acrylates, epoxy poly(meth)acrylates, polyester
poly(meth)acrylates and polyurethane poly(meth) acrylates.
4. A method of adhesion as claimed in claim 1, wherein the amount
of the application rate is one providing a coating film of a
thickness of about 10 to 300 .mu..
5. A method of adhesion as claimed in claim 1, wherein the light is
ultraviolet light generated by a high-voltage mercury lamp.
Description
The present invention relates to a method of adhesion for a
two-step, reactive type photocurable tacky.adhesive agent and a
composition therefor.
A tacky.adhesive agent, which exhibits satisfactory adhesiveness
within a certain period of time after being applied to a substrate,
thus permitting the procedure of bonding together to be conducted,
and also allows a chemical reaction to go to completion after the
elapse of a certain period of time, thereby demonstrating excellent
bonding strength, can eliminate the necessity of clamping
subsequent to the bonding together of substrates and is earnestly
desired in various industrial sectors where adhesives are
utilized.
The fundamental principle of adhesion lies in the wetting of
surfaces to be bonded, and for the purpose of spreading uniformly
over substrates, it is required of adhesives to possess a viscosity
of not more than about 1 million centipoises.
In order to secure satisfactory adhesiveness, on the other hand,
adhesives have to show a viscosity in the neighborhood of several
ten million centipoises.
Conventional two-component, reactive type tacky. adhesive agents
are designed to develop adhesiveness by allowing a fixed length of
open time after the uniform application on substrates and then
causing thickening to take place. In the case of non-solvent types,
such a phenomenon can be achieved by allowing a chemical reaction
to proceed to a limited extent, but heat and time are required. In
the case of solvent types, heat for a given period of time is
applied to evaporate the solvent, whereby there is encountered the
problem of environmental pollution due to the evaporation of
solvent.
The present inventors, with a specific view to solving the problems
of conventional two-component, reactive type tacky.adhesive agents,
conducted extensive investigation, and as a result, found that a
two-step reactive type tacky. adhesive agent containing a component
curable by light and a component curable through a chemical
reaction, while remaining in the form of a non-solvent or
high-solid liquid with a relatively low viscosity enough to permit
uniform spreading on substrates within a certain period of time
after the compounding of the two component, is applied on a
substrate and exhibits satisfactory adhesiveness, upon irradiation
with light through the polymerization of the photopolymerizable
component, within a time as short as 0.1 to 60 seconds, whereby the
substrate and other substrate are bonded together with satisfactory
adhesiveness being retained, and can produce excellent bonding
properties by curing the component curable through a chemical
reaction to thereby form a network structure having the former and
latter components mutually permeated. The finding has culminated in
the present invention.
Thus, the present invention is directed toward a method of adhesion
which comprises applying a two-step reactive type photocurable
tacky.adhesive agent comprising (1) a non-photopolymerizable epoxy
resin or isocyanate compound, (2) a curing agent therefor and (3) a
compound having at least one photopolymerizable vinyl group in one
molecule onto a substrate, irradiating the whole applied surface
with light to develop tackiness, and adhering the substrate to a
material to be bonded thereto, while the tackiness is retained,
followed by curing, and toward a two-step, reactive type
tacky.adhesive agent comprising (1) a non-photopolymerizable epoxy
resin or isocyanate compound, (2) a curing agent therefor and (3) a
compound having at least one photopolymerizable vinyl group in one
molecule, in which the said agent, after being irradiated with
light, exhibits a glass transition temperature of not higher than
about 40.degree. C.
The method of adhesion according to the present invention,
providing excellent green bonding strength, can permit satisfactory
adhesion without clamping, and can be particularly suitably
utilized in the adhesion of materials to be bonded which have a
curved surface difficult to be clamped.
The adhesive which constitutes a base in the two-step, reactive
type tacky.adhesive agent according to the present invention
includes, for example, a non-solvent or high-solid, two-component,
reactive type of non-photopolymerizable epoxy-based adhesive, or
two-component, reactive type of urethane-based adhesive. The
non-photopolymerizable epoxy-based adhesives are ones which do not
undergo photopolymerization under ordinary conditions. The resin
component in the two-component reactive type of
non-photopolymerizable epoxy-based adhesives is understood to
comprehend non-solvent or high-solid epoxy resins, and includes,
for example, glycidyl ether based epoxy resins, such as bisphenol A
epoxy resins, bisphenol F epoxy resins, hydrogenated bisphenol A
epoxy resins, novolac epoxy resins, polyglycidyl ethers of
polyalkylene glycols being exemplified by diglycidyl ether of
neopentyl glycol; glycidylamine based epoxy resins, such as
triglycidylisocyanurate and tetraglycidyl-m-xylenediamine; glycidyl
ester based epoxy resins, such as polyglycidyl esters of
polycarboxylic acids being exemplified by diglycidyl phthalate and
diglycidyl hexahydrophthalate; and cyclic aliphatic type epoxy
resins, such as vinylcyclohexene dioxide,
3,4-epoxycyclohexylmethyl(3,4-epoxycyclohexane)carboxylate and
bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate. In addition to
these, there are also mentioned epoxy-containing resins formed by
the reaction of epoxy resins with polybasic acids or polyester
polycarboxylic acids, polyglycidyl esters of polyester
polycarboxylic acids, or polyglycidyl ethers of polyester polyols,
and the like. The polybasic acid includes, for example, maleic acid
(anhydride), succinic acid (anhydride), adipic acid, fumaric acid,
phthalic acid (anhydride), terephthalic acid, isophthalic acid,
methyltetrahydrophthalic acid (anhydride), tetrahydrophthalic acid
(anhydride), sebacic acid, dodecandioic acid, azelaic acid,
glutaric acid, trimellitic acid (anhydride), hexahydrophthalic acid
(anhydride) and dimer acids (e.g., Bersadime.RTM. 216, 228, 288,
etc. with an acid value of 191 to 198, produced by Henkel Japan Co.
of Japan). The terms "polyester polycarboxylic acid" and "polyester
polyol" denote polyester polycarboxylic acids and polyester polyols
obtained by esterification according to conventional methods of
these polybasic acids with polyhydric alcohols, such as ethylene
glycol, propylene glycol, butylene glycol, hexylene glycol,
decanediol, neopentyl glycol, glycerol, trimethylolpropane,
1,4-cyclohexanedimethanol, neopentyl glycol
hydroxypivalate,l,4-cyclohexanediol and hydrogenated bisphenol A,
respectively.
The curing agent for the above-mentioned epoxy resins includes, for
example, aliphatic polyamines, such as diethylenetriamine,
triethylenetetramine, tetraethylenepentamine, dipropylenediamine,
diethylaminopropylamine, menthanediamine, and isophorondiamine;
aromatic amines, such as xylylenediamine, m-phenylenediamine,
diaminodiphenylmethane and diaminodiphenylsulfone; polyamideamines
obtained, for example, by the reaction of dimer acids (e.g.,
Bersadime.RTM. 216, 228, 288, etc. with an acid value of 191 to
198, produced by Henkel Japan Co. of Japan) with diamines;
mercaptan compounds, such as trimethylolpropane
tris-(.beta.-thiopropionate) and compounds represented by the
formula ##STR1## (wherein R is an aliphatic hydrocarbon; n is 1 to
2); acid anhydrides, such as phthalic anhydride, maleic anhydride,
trimellitic anhydride, dodecynylsuccinic anhydride,
(methyl)hexahydrophthalic anhydride and methylnadic anhydride;
polybasic acids, such as dimer acids (e.g., Bersadime.RTM. 216,
228, 288, etc. with an acid value of 191 to 198, produced by Henkel
Japan Co. of Japan) and octadecanedicarboxylic acid; epoxy
polymerization catalyst type of curing agents, such as
2,4,6-tris(dimethylaminomethyl)phenol, benzyldimethylamine and
imidazole; and others, such as dicyandiamide, organic acid
dihydrazides and phenol resins. Such curing agents can be used
solely or in combinations of not less than two kinds.
The formulating ratio of epoxy resin and curing agent therefor is
desirably such as: the number of epoxy groups against the number of
active hydrogens in amino groups may be about 0.1 to 3.0 in the
case of polyamines used as a curing agent; the number of epoxy
groups against the number of thiol groups may be about 0.1 to 3.0
in the case of mercaptan compounds employed as a curing agent; the
number of epoxy groups against the number of acid anhydride groups
may be about 0.3 to 3.0 in the case of acid anhydrides utilized as
a curing agent; and the number of epoxy groups against the number
of carboxyl groups may be about 0.3 to 3.0 in the case of polybasic
acids used as a curing agent.
The resin component in the two-component, reactive type
urethane-based adhesives is understood to comprehend non-solvent or
high-solid isocyanate compounds, and includes, for example,
aromatic, aliphatic, alicyclic and aromatic-aliphatic
diisocyanates, such as tolylene diisocyanate, diphenylmethane
diisocyanate (which may be either in the form of crude or purified
product), 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate,
naphthylene-1,5-diisocyanate, phenylene diisocyanate, xylylene
diisocyanate, 1,6-hexamethylene diisocyanate, 1,4-tetramethylene
diisocyanate, isophoron diisocyanate, hydrogenated tolylene
diisocyanate, hydrogenated diphenylmethane diisocyanate and
hydrogenated xylylene diisocyanate; or dimers or trimers of the
above-mentioned diisocyanates, or adducts of the above-mentioned
diisocyanates with active hydrogen compounds, such as adducts of
the above-described diisocyanates with ethylene glycol, propylene
glycol, tetramethylene glycol, neopentyl glycol, butanediol,
1,6-hexanediol, polyethylene glycol, polypropylene glycol,
polytetramethylene ether glycol, trimethylolpropane, glycerol,
pentaerythritol, castor oil, bisphenol A-ethylene oxide adducts and
bisphenol A-propylene oxide adducts and polyesterpolyols formed by
the esterification according to the conventional method of
polybasic acids, such as maleic acid (anhydride), succinic acid
(anhydride), adipic acid, fumaric acid, phthalic acid (anhydride),
terephthalic acid, isophthalic acid, methyltetrahydrophthalic acid
(anhydride), tetrahydrophthalic acid (anhydride), sebacic acid,
dodecane diacid, azelaic acid, glutaric acid, trimellitic acid
(anhydride), hexahydrophthalic acid (anhydride) and dimer acids
(e.g., Bersadime.RTM. 216, 228, 288 etc. with an acid value of 191
to 198, produced by Henkel Japan Co. of Japan) and aliphatic
glycols, such as ethylene glycol, propylene glycol, butylene
glycol, hexylene glycol, decanediol and neopentyl glycol, aliphatic
polyether glycols suchas diethylene glycol and dipropylene glycol,
and polyhydric alcohols, such as glycerol, trimethylolpropane,
1,4-cyclohexanedimethanol, hydroxypivalic acidneopentyl glycol
ester, 1,4-cyclohexanediol and hydrogenated bisphenol A. These
isocyanate compounds can be employed solely or in combination of
not less than two kinds thereof.
The curing agent for the above-mentioned isocyanate compounds
includes, for example, active hydrogen compounds, such as ethylene
glycol, propylene glycol, tetramethylene glycol, neopentyl glycol,
butanediol, 1,6-hexanediol, polyethylene glycol, polypropylene
glycol, polytetramethylene ether glycol, trimethylolpropane,
glycerol, pentaerythritol, castor oil, bisphenol-A ethylene oxide
adducts, bisphenol-A propylene oxide adducts, and polyester polyols
formed by the esterification according to the conventional method
of polybasic acids, such as maleic acid (anhydride), succinic acid
(anhydride), adipic acid, fumaric acid, phthalic acid (anhydride),
terephthalic acid, isophthalic acid, methyltetrahydrophthalic acid
(anhydride), tetrahydrophthalic acid (anhydride), sebacic acid,
dodecanediacid, azelaic acid, glutaric acid, trimellitic acid
(anhydride), hexahydrophthalic acid (anhydride) and dimer acids
(e.g., Bersadime.RTM. 216, 228, 288, etc. with an acid value of 191
to 198, produced by Henkel Japan Co. of Japan), and aliphatic
glycols, such as ethylene glycol, propylene glycol, butylene
glycol, hexylene glycol, decanediol and neopentyl glycol, aliphatic
polyether glycols, such as diethylene glycol and dipropylene
glycol, and polyhydric alcohols, such as glycerol,
trimethylolpropane, 1,4-cyclohexanedimethanol, hydroxypivalic
acidneopentyl glycol ester, 1,4-cyclohexanediol and hydrogenated
bisphenol A, or there may be mentioned acrylic polymers having
hydroxyl or amino groups in the side chains.
Such acrylic polymers are obtained, for example, by polymerizing in
accordance with the per se known vinyl polymerization such
hydroxyl-containing vinyl monomers and amino-containing vinyl
monomers as N-methylol(meth)acrylamides,
hydroxyethyl(meth)acrylates, hydroxypropyl(meth)-acrylates,
pentaerythritol mono(meth)acrylates, allyl alcohol, monoesters of
polyethylene glycol with (meth)-acrylic acids, monovinyl ether of
ethylene glycol or polyethylene glycol, monovinyl ether of
propylene glycol or polypropylene glycol and Placce.RTM. FA-1
(CH.sub.2 =CHCOOCH.sub.2 CH.sub.2 OCO(CH.sub.2).sub.5 OH) produced
by Daicel Chemical Industries, Ltd. of Japan), primary- or
secondary-amino group containing vinyl monomers, such as aminoethyl
(meth)-acrylates, N-methylamino(meth)acrylates,
N-ethylaminoethyl(meth)acrylates, allylamine and diallylamine with
vinyl monomers such as methyl(meth)acrylates,
ethyl(meth)-acrylates, n-butyl(meth)acrylates,
isobutyl(meth)acrylates, 1-ethylpropyl(meth)acrylates,
1-methylpentyl(meth)acrylates, 2-methylpentyl(meth)acrylates,
3-methylpentyl(meth)acrylates, 1-ethylbutyl(meth)acrylates,
2-ethylbutyl(meth)acrylates, 2-ethylhexyl(meth)acrylates,
isooctyl(meth)acrylates, 3,5-5-trimethylhexyl(meth)acrylates,
decyl(meth)acrylates, dodecyl(meth)acrylates and
tetrahydrofurfuryl(meth)acrylates and acrylic acid, methacrylic
acid, maleic acid, maleic anhydride, fumaric acid, maleic acid
monoesters and itaconic acid, glycidyl(meth)acrylates, glycidyl
allyl ether, styrene, vinyl acetate, acrylonitrile,
methacrylonitrile or vinyl ether.
Or, the photopolymerizable vinyl compound to be described below in
some. instances contains functional groups which are reactive with
the isocyanate group, such as hydroxyl and amino groups, and in
such cases, the photopolymerizable vinyl compound, as such, can be
used as a curing agent, thus eliminating occasionally the necessity
of employing the above-described curing agent.
These curing agents can be used, either alone or in combination of
not less than two kinds thereof. Also, the per se known catalysts
can be used for the isocyanate compounds and curing agents
therefor.
The proportion in which the isocyanate compound and curing agent
therefor are formulated is favorably in such a ratio that the sum
of the number of the active hydrogen groups in the curing agent and
the number of the hydroxyl groups or amino groups in the
below-described photopolymerizable vinyl compound may be about 0.1
to 5.0 against a number of the isocyanate groups.
The above two-component, reactive type adhesive is admixed with a
photocurable (photopolymerizable) component to impart the
photocurable property. Such a photocurable component includes, for
example, a photopolymerizable vinyl compound such as vinyl
monomers, poly(meth)acrylates, epoxy poly(meth)acrylates, polyester
poly(meth)acrylates, polyurethane poly(meth)acrylates,
polybutadiene poly(meth)-acrylates, photopolymerizable vinyl
oligomers and vinyl polymers.
Specific examples of the vinyl monomers include, for example,
methyl(meth)acrylates, ethyl(meth)acrylates,
n-butyl(meth)acrylates, isobutyl(meth)acrylates,
1-ethylpropyl(meth)acrylates, 1-methylpentyl(meth)acrylates,
2-methylpentyl(meth)acrylates, 3-methylpentyl(meth)acrylates,
1-ethylbutyl(meth)acrylates, 2-ethylbutyl(meth)acrylates.
2-ethylhexyl(meth)acrylates, isooctyl(meth)acrylates,
3,5,5-trimethylhexyl(meth)acrylates, decyl(meth)acrylates,
dodecyl(meth)acrylates and tetrahydrofurfuryl(meth)acrylates,
acrylic acid, methacrylic acid, maleic acid, maleic anhydride,
fumaric acid, maleic acid monoesters and itaconic aicd,
N-methylol(meth)acrylamides, hydroxyethyl(meth)acrylates,
hydroxypropyl(meth)acrylates, pentaerythritol mono(meth)acrylates,
allyl alcohol, monoesters of polyethylene glycol with (meth)acrylic
acids, monovinyl ether of ethylene glycol or polyethylene glycol,
monovinyl ether of propylene glycol or polypropylene glycol and
Placcel.RTM. FA-1 (CH.sub.2 .dbd.CHCOOCH.sub.2 CH.sub.2
OCO(CH.sub.2).sub.5 OH) produced by Daicel Chemical Industries,
Ltd. of Japan, aminoethyl(meth)acrylates,
N-methylaminoethyl(meth)acrylates,
N-ethylaminoethyl(meth)acrylates, allylamine, diallylamine,
glycidyl(meth)acrylates, glycidylallyl ether, styrene, vinyl
acetate, acrylonitrile, methacrylonitrile and vinyl ether.
Specific examples of the above-mentioned poly(meth)-acrylates
include, for example, di-, tri- and tetraethylene glycol
di(meth)acrylates, dipropylene glycol di(meth)acrylates,
dipentamethylene glycol di(meth)acrylates, tetraethylene glycol
di(meth)acrylates, tetraethylene glycol dichloroacrylate,
diglycerol di(meth)acrylates, diglycerol tetra(meth)acrylates,
tetramethylene di(meth)-acrylates, ethylene di(meth)acrylates,
neopentyl glycol di(meth)acrylates, trimethylolpropane
tri(meth)acrylates, pentaerythritol di(meth)acrylates,
pentaerythritol tri(meth)-acrylates, 1,6-hexanediol
di(meth)acrylates and NK ester.RTM.BPE200 (produced by
Shin-Nakamura Kagaku Kogyo Co. of Japan) represented by
##STR2##
The epoxy poly(meth)acrylates include, for example, those formed by
the reaction of an epoxy-containing compound with, for example,
acrylic acid or methacrylic acid, and their specific examples
include methacrylic acid adducts (Epoxy ester.RTM.40EM, produced by
Kyoeisha Oils & Fats Co. of Japan) represented by: ##STR3##
acrylic acid adducts (Epoxy ester.RTM.70PA) represented by:
##STR4## acrylic acid adducts (Epoxy ester.RTM.80MFA) represented
by: ##STR5## methacrylic acid adducts (Epoxy ester.RTM.3002M)
represented by: ##STR6## and acrylic acid adducts (Epoxy
ester.RTM.3002A) represented by: ##STR7## while the polyester
poly(meth)acrylates includes, for example, those formed by the
reaction of a polyester polyol with, for example, acrylic acid, and
their specific examples include for example, HX-220 (produced by
Nippon Kayaku Co., Ltd, of Japan) represented by: ##STR8## and
HX-620 represented by: ##STR9## (wherein m+n=4, m, m: an integer of
1 of 3)
The polyurethane poly(meth)acrylates include, for example, reaction
products of an isocyanate-containing compound, for example,
aromatic, aliphatic, alicyclic and aromatic-aliphatic
diisocyanates, such as tolylene diisocyanate, diphenylmethane
diisocyanate (which may be either in the form of crude or purified
product), 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate,
naphthylene1,5-diisocyanate, phenylene diisocyanate, xylylene
diisocyanate, 1,6-hexamethylene diisocyanate, 1,4-tetramethylene
diisocyanate, isophoron diisocyanate, hydrogenated tolylene
diisocyanate, hydrogenated diphenylmethane diisocyanate and
hydrogenated xylylene diisocyanate; or dimers or trimers of the
above-mentioned diisocyanates, or adducts of the above-mentioned
diisocyanates with active hydrogen compounds, such as adducts of
the above-described diisocyanates with ethylene glycol, propylene
glycol, tetramethylene glycol, neopentyl glycol, butanediol,
1,6-hexanediol, polyethylene glycol, polypropylene glycol,
polytetramethylene ether glycol, trimethylolpropane, glycerol,
pentaerythritol, castor oil, bisphenol A-ethylene oxide adducts and
bisphenol A-propylene oxide adducts or polyester polyols formed by
the esterification according to the conventional method of
polybasic acids, such as maleic acid (anhydride), succinic acid
(anhydride), adipic acid, fumaric acid, phthalic acid (anhydride),
terephthalic acid, isophthalic acid, methyltetrahydrophthalic acid
(anhydride), tetrahydrophthalic acid (anhydride), sebacic acid,
dodecandioic acid, azelaic acid, glutaric acid, trimellitic acid
(anhydride), hexahydrophthalic acid (anhydride) and dimer acids
(e.g., Bersadime.RTM. 216, 228, 288, etc. with an acid value of 191
to 198), and aliphatic glycols, such as ethylene glycol, propylene
glycol, butylene glycol, hexylene glycol, decanediol, neopentyl
glycol, aliphatic polyether glycols such as diethylene glycol,
dipropylene glycol, and polyhydric alcohols, such as glycerol,
trimethylolpropane, 1,4-cyclohexanedimethanol, neopentyl glycol
hydroxypivalate, 1,4-cyclohexanediol and hydrogenated bisphenol A,
with a hydroxyl-containnig vinyl monomer, for example
N-methylol(meth)acrylamides, hydroxyethyl (meth)acrylates,
hydroxypropyl (meth)acrylates, pentaerythritol
mono(meth)-acrylates, allyl alcohol, monoesters of polyethylene
glycol with (meth)acrylic acids, monovinyl ether of ethylene glycol
or polyethylene glycol, monovinyl ether of propylene glycol or
polypropylene glycol and Placcel.RTM. FA-1 (CH.sub.2
.dbd.CHCOOCH.sub.2 CH.sub.2 OCO(CH.sub.2).sub.5 OH), produced by
Daicel Chemical Industries, Ltd. of Japan.
These products are normally formed by reacting one isocyanate
equivalent weight of the isocyanate-containing compound with one
hydroxyl equivalent weight of the hydroxylcontaining vinyl
monomer.
The polybutadiene poly(meth)acrylates include, for example, those
formed by the reaction of polybutadiene diol with methacrylic acid,
acrylic acid, etc., and their specific examples include, for
example, Quinbeam.RTM. 101 with a vinyl equivalent of 355 and
viscosity of 21,000 centipoises (25.degree. C.) produced by Nippon
Zeon Co., Ltd. of Japan.
Out of the above-described photopolymerizable vinyl compounds,
particularly, vinyl compounds having at least two
photopolymerizable vinyl groups per molecule, such as
poly(meth)acrylates, epoxy poly(meth)acrylates, polyester
poly(meth)acrylates, polyurethane poly(meth)-acrylates and
polybutadiene poly(meth)acrylates, result in development of the
tackiness within a short period of time after irradiation with
light, and are especially suitable.
Of the above photopolymerizable vinyl compounds, those with a high
viscosity consist of epoxy poly(meth)-acrylates, polyester
poly(meth)acrylates, polyurethane poly(meth)acrylates and
polybutadiene poly(meth)acrylates, and when these high-viscosity
compounds are used, other low-viscosity photopolymerizable vinyl
compounds are utilized in combination therewith to produce
non-solvent or high-solid liquid tacky.adhesive agents with a
relatively low viscosity.
The two-step, reactive type of tacky.adhesive agents according to
the present invention can be obtained by the mixing of the
above-mentioned epoxy resin or isocyanate compound, curing agent
therefor and photopolymerizable vinyl compound.
The proportion in which the photopolymerizable compound is used is
preferably about 5 to 80 weight % against the total amount of
tacky.adhesive agent, more preferably in the range of about 10 to
60 weight %.
In cases in which the base resin is an epoxy resin, with the curing
agent being an amine compound and/or a mercaptan compound, the
photopolymerizable vinyl compound, when admixed with the curing
component agent, sometimes undergoes the Michael reaction between
its vinyl groups and the curing agent, thus bringing about
deterioration in storage stability, and therefore, is preferably
added to the epoxy component resin which is the resin component.
When the curing agent is an acid anhydride and/or a polybasic acid,
such a photopolymerizable compound may be added either to the resin
component or the curing component agent.
When the base resin is an isocyanate compound, further, the
photopolymerizable vinyl compound in the present invention in many
cases contains functional groups which are reactive such as
hydroxyl or amino groups, and therefore, it is also considered
common from the standpoint of improved storage stability to add
such a photopolymerizable vinyl compound to the curing component
agent composed principally of hydroxyl-containing compounds.
The tacky.adhesive agent which is used in the present invention, in
principle, is of a two-component type. However, when the base resin
for the tacky.adhesive agent is urethane-based, photopolymerizable
vinyl compounds not containing functional groups reactive with the
isocyanate group, such as hydroxyl group, can provide excellent
storage stability even after compounded with the isocyanate
compound constituting resin component into a one-component
solution, and therefore permit the formulation into a one-component
composition.
In the case of such a one-component type composition, tackiness is
developed by irradiation with light, followed by adhering together
with a material to be bonded thereto and thereafter, the isocyanate
groups are allowed to undergo moisture-curing in accordance with
the per se known method to produce the bonding strength or
adhesiveness.
The tacky.adhesive agent which is used in the present invention
comprises the above-described three components, whereby the said
composition, after irradiated with light (above 0.1 second to 60
minutes), favorably exhibits a glass transition temperature of not
higher than about 40.degree. C., particularly not higher than about
20.degree. C. When the glass transition temperature is in excess of
40.degree. C., the resulting coating film shows inferior
wettability, thus making it impossible to stick together with the
other material to be bonded thereto.
The light (photo) in the above mentioned photopolymerizable vinyl
compound denotes primarily ultraviolet rays having the wavelength
range of about 180 nm to 460 nm, and the source of generating
ultraviolet radiation includes, for example, low-voltage mercury
lamp, medium-voltage mercury lamp, high-voltage mercury lamp,
ultra-high-voltage mercury lamp, xenon mercury lamp, ultraviolet
fluorescent lamp and carbon arc lamp. In the present invention,
furthermore, there can also be used radiations, such as
.alpha.-rays, .beta.-rays, .gamma.-rays, X rays and electron
rays.
The tacky.adhesive agent according to the present invention
develops rapidly adhesiveness through irradiation with light, and
when a promoter is contained therein in order to promote further
the development of adhesiveness, it can produce desirable effects.
When the light is ultraviolet rays, light sensitizers are used.
Suitably usable light sensitizers include, for example, benzoin
compounds, such as benzoin, benzoin methyl ether, benzoin ethyl
ether, benzoin isobutyl ether and benzoin octyl ether, carbonyl
compounds, such as benzil, diacetyl, diethoxyacetophenone,
2-hydroxy-2-methylpropiophenone,
4'-isopropyl-2-hydroxy-2-methylpropiophenone, methylanthraquinone,
acetophenone, benzophenone and methyl benzoylformate, sulfur
compounds, such as diphenyldisulfide and dithiocarbamate,
naphthalene compounds, such as .alpha.-chloromethylnaphthalene,
metal salts, such as iron chloride, and anthracene. The amount of
the light sensitizer to be used is in the range of about 0.01 to 20
parts by weight against 100 parts by weight of photopolymerizable
vinyl compound, preferably in the range of about 0.1 to 10 parts by
weight.
When the light is ionizing radiations, such as electron rays and
.gamma.-rays, the tacky.adhesive agent develops adhesiveness
swiftly without the use of light sensitizer, and there is no need
to use light sensitizers particularly.
The tacky.adhesive agent of the present invention can allow
addition of, in addition to the above principal components, per se
known fillers, softeners, antioxidants, tackifying resins, adhesion
promoters and plasticizers.
This tacky.adhesive agent is a non-solvent or high-solid liquid
which exhibits a viscosity relatively low enough to permit the
uniform application to substrates within a limited period of time
of about 50 hours after mixing the resin component of
two-component, reactive type adhesive and a curing agent therefor
with a photopolymerizable vinyl compound, and can be applied
uniformly to substrates. In the present invention, the mixture is
first applied to a substrate. The application rate is in such an
amount as may provide a coating film of a thickness of about 10 to
300 .mu., preferably about 20 to 200 .mu.. After the application,
the whole applied surface is irradiated with light, whereby there
develops such a degee of tackiness as may permit the adhering
together of the substrate in a length of time as short as about 0.1
to 60 seconds, and the improved green bonding strength produced can
allow satisfactorily the adhesion not only under pressure but also
without clamping. After the sticking together to a material to be
bonded, the component being curable through the chemical reaction
at room temperature or under heating may be allowed to cure.
As the substrate or material to be bonded, there can be used every
kinds of materials, such as metal, glass, plastics, wood, particle
board, paper, slates, rubber, and decorative sheet.
According to the present invention, there appears, with a period of
time as short as about 0.1 to 60 seconds, tackiness of such a
magnitude as may enable the sticking together of materials to be
bonded. The tackiness is in the range of about 1 to 10
kg/25.times.25 mm.sup.2 as holding strength.
The method of the present invention can permit the adhesion of
materials to be bonded to substrates not only having the flat
surface but also the curved surface difficult to be clamped. In the
case of a substrate having a curved surface, the substrate may only
be bonded under pressure to the adhesive-applied surface by such a
means as a roller.
The examples are described below to illustrate the present
invention more specifically.
In the examples, the term "part" denotes a part by weight.
EXAMPLE 1
To 100 parts of an epoxy resin (Epotohto.RTM. YD-128; produced by
Tohto Kasei Co. of Japan, with an epoxy equivalent of 189 and a
viscosity of 13,000 centipoises (25.degree. C.)) was added 50 parts
of a mixture consisting of 60 parts of an epoxy diacrylate (Epoxy
ester.RTM.3002A; produced by Kyoeisha Oils & Fats Co. of Japan,
with a vinyl equivalent of 300 and a viscosity of 50,000
centipoises (25.degree. C)), 15 parts of n-butyl acrylate, 15 parts
of 2-ethylhexyl acrylate, 10 parts of glycidyl methacrylate and 3
parts of 2-hydroxy-2-methylpropiophenone to thereby make the Resin
Component 1.
On the other hand, 100 parts of a polyamideamine formed by the
reaction of 572 parts of a dimer acid (Bersadime.RTM. 288; produced
by Henkel Japan Co. of Japan, with an acid value of 196) with 210
parts of diethylenetriamine was admixed with 5 parts of
2,4,6-tris(dimethylaminomethyl)phenol, and the resulting resin
(with a viscosity of 42,000 centipoises (25.degree. C.)) was made
the Curing Agent 1. 100 parts of the Resin Component 1 was mixed
with 50 parts of the Curing Agent 1, and the mixture was applied on
the surface of an FRP, followed by irradiation, 10 cm apart from
the above for 5 seconds, with ultraviolet rays generated by a
high-voltage mercury lamp, whereby the applied surface, with its
ball tack(Note) of 29/32 inch, showed good tackifying strength.
Subsequently, this tacky. adhesive agent was applied to the FRP
surface having a curved-surface portion, and after the whole
applied surface was irradiated with light in the same manner as
described above, a 0.7-mm thick ABS plate treated with corona
discharge was adhered to the substrate. The assembly was allowed to
stand without clamping at 30.degree. C. for 15 hours, and
90.degree. C. peeling-off bonding strength was measured in the
measuring atmosphere of a tensile rate of 100 mm/min, temperature
of 23.degree. C. and relative humidity of 50%, with the result that
the ABS ruptured at not less than 10 kg/25 mm and that the curved
surface portion also showed good adhesion. With the assembly formed
by treating iron/iron ground with #240 sandpaper used as substrates
under the same ultraviolet irradiation conditions and curing
conditions, the tensile shear bonding strength was measured at a
tensile rate of 5 mm/min under a measuring atmosphere (23.degree.
C. and relative humidity of 50%), and was found to be 170
kg/cm.sup.2. The mixture consisting of 100 parts of the Resin
Component 1 and 50 parts of the Curing Agent 1 showed a pot life of
60 minutes at 25.degree. C.
EXAMPLE 2
To 100 parts of polytetramethylene ether glycol (with an OH
equivalent of 325) having a molecular weight of 650 was added 150
parts of a photopolymerizable component obtained by the compounding
of 40 parts of an epoxy dimethacrylate (Kyoeisha Oils & Fats
Co. of Japan, Epoxy ester.RTM.3002M; with a vinyl equivalent of 314
and a viscosity of 50,000 centipoises (25.degree. C.)), 20 parts of
a polyester diacrylate (produced by Nippon Kayaku Co., Ltd. of
Japan, HX-220; with a vinyl equivalent of 270 and a viscosity of
100 centipoises (25.degree. C.)), 20 parts of Placce.RTM. FA-1
produced by Daicel Chemical Industries Ltd. of Japan, 20 parts of
tetrahydrofuryl methacrylate and 2 parts of methyl benzoylformate
to thereby make the Curing Agent 2 (with an OH equivalent of 394).
On the other hand, 853 parts of crude diphenylmethanediisocyanate
was reacted with 184 parts of castor oil and 132 parts of
polypropylene glycol (with an OH equivalent of 500) having a
molecular weight of 1000, and the resulting product (with an amine
equivalent of 200) was made the Resin Component 2. 20 parts of the
Resin Component 2 was mixed with 25 parts of the Curing Agent 2,
and the ball tack(Note) was measured under the same light
irradiation conditions as Example 1 and found to be 25/32 inch.
Subsequently, this tacky.adhesive agent was applied (thickness of
coating film of 100 .mu.) to a #240 sand-paper ground iron plate
having a curved surface portion, and after the whole applied
surface was irradiated with light in the same manner as described
in Example 1, a 0.5-mm thick polypropylene plate was adhered to the
substrate. The assembly was allowed to stand without clamping at
25.degree. C. for 24 hours, and 90.degree. peeling-off bonding
strength was measured in the measuring atmosphere of a tensile rate
of 100 mm/min, temperature of 23.degree. C. and relative humidity
of 50%, with the result that the polypropylene ruptured at not less
than 8 kg/25 mm and that the curved surface portion also showed
good adhesion.
Then, the tensile shear bonding strength was measured with the
substrates similar to the one in Example 1 under the
light-irradiation, curing and measuring conditions similar to those
of Example 1, and found to be 150 kg/cm.sup.2. The mixed solution
consisting of 20 parts of the Resin Component 2 and 25 parts of the
Curing Agent 2 showed a pot life of 50 minutes at 25.degree. C.
(Note): Ball tack ... In accordance with the J. Dow method. Method
of measuring the tackifying strength:
32 different steelballs having a diameter ranging from 1/32 inch to
32/32 inch made available for the test are allowed to roll down a
slope at 30.degree. of angle of inclination which contains a 10-cm
long surface applied with a tacky material, with an approach run of
10 cm, and the diameter of the largest-sized steel ball which stops
on the said 10-cm long surface applied with a tacky material is
taken as a measure for the adhesiveness of such a material.
EXAMPLE 3
A 60 parts portion of a mixture consisting of 30 parts of Epoxy
ester.RTM.3002A as used in Example 1, 30 parts of triethylene
glycol diacrylate, 30 parts of 1-ethylpropyl methacrylate, 10 parts
of glycidyl allyl ether and 5 parts of benzoin ethyl ether was
added to 100 parts of Epotohto.RTM. YD-128 to form Resin Component
3.
On the other hand, 5 parts of 2,4,6-tris(dimethylaminomethyl)phenol
was added to 100 parts of the polyamideamine obtained by reacting
572 parts of Bersadime.RTM. 288 as used in Example 1 with 295 parts
of triethylenetetramine to form a resin (with a viscosity of 13,000
centipoises (25.degree. C.)), and the resin was made Curing Agent
3.
100 parts of Resin Component 3 was mixed with 40 parts of Curing
Agent, and the mixture was applied to an FRP surface, which was
irradiated, from above and 10 cm apart, with ultraviolet light
generated by a high-voltage mercury lamp for 7 seconds. A
corona-discharge treated, 1.5 mm thick polyethylene plate having a
warped, curved surface formed was adhered to the FRP substrate
using a roller, and the as was allowed to stand at 25.degree. C.
for 24 hours, whereby the FRP and polyethylene plate showed good
adhesion. The mixture consisting of 100 parts of Resin Component 3
and 40 parts of Curing Agent 3 exhibited a pot life of 80 minutes
at 25.degree. C.
EXAMPLE 4
By reacting 1350 parts of a reaction product of 1000 parts of
polypropylene glycol having a molecular weight of 1000 and an OH
equivalent of 500 and 350 parts of tolylene diisocyanate with 235
parts of hydroxyethyl acrylate, there was obtained a urethane
diacrylate. 50 parts of a mixture consisting of 70 parts of the
urethane diacrylate, 20 parts of n-butyl acrylate, 10 parts of
hydroxyethyl acrylate and 3 parts of
2-hydroxy-2-methylpropiophenone was added to 50 parts of
Epotohto.RTM.YD-128 as used in Example 1 to make Resin Component
4.
100 parts of Resin Component 4 was mixed with 45 parts of Curing
Agent 3 as used in Example 3, and the mixture was applied (to a
thickness of coating film of 100 .mu.) to an iron plate ground with
#240 sand paper, followed by irradiation 10 cm apart from above
with ultraviolet rays generated by a high-voltage mercury lamp for
15 seconds. A 50 .mu. thick polyethylene terphthalate film was
adhered to the iron plate with the bonding surface area of 25
mm.times.25 mm=625 mm.sup.2, and immediately thereafter, a weight
of 4 kg was put on the lower end of the non-bonded portion of the
polyethylene terephthalate film. The bonded assembly was suspended
in an atmosphere of 25.degree. C., whereby there was no slippage
observed at the bonded area one day later, with the bond being
cured.
Then, this tacky.adhesive agent was applied on a sheet of particle
board (to a thickness of coating film of 100 .mu.), and the whole
applied surface was irradiated with light in the same manner as
described above, followed by sticking together with use of rollers
of a 0.6 mm thick decorative sheet of natural wood having warpage
and curved surface formed thereon. The bonded assembly, upon
standing without clamping at 25.degree. C. for 24 hours, showed
excellent bonding, without swelling produced between the particle
board and decorative sheet.
EXAMPLE 5
By mixing 100 parts of an acrylic polyol (with an average molecular
weight of 150,000 and an OH equivalent of 580) formed from the
vinyl polymerization of 80 parts of n-butyl acrylate and 20 parts
of hydroxyethyl acrylate, with 60 parts of n-butyl acrylate, 26
parts of hydroxyethyl acrylate and 3 parts of
2-hydroxy-2-methylpropiophenone, there was prepared Curing Agent 5
(with an OH equivalent of 482 and a viscosity (at 25.degree. C.) of
1,600 cps.)
50 parts of an adduct of tolylene diisocyanate with trimethylol
propane (Takenate.RTM.D-103 produced by Takeda Chemical Industries,
Ltd. of Japan; with an amine equivalent of 328 and a viscosity (at
25.degree. C.) of 1,000 cps) used as Resin Component 5 was mixed
with 100 parts of Curing Agent 5, and the mixture was applied on an
iron plate ground with #240 sand paper (to a thickness of coating
film of 100 .mu.), followed by irradiation 10 cm apart from above
with ultraviolet rays generated by a high-voltage mercury lamp for
3 seconds. A 50 .mu. thick polyethylene terephthalate film was
adhered to the iron plate with the bonding surface area of 25
mm.times.25 mm=625 mm.sup.2, and immediately thereafter, a weight
of 4 kg was put on the lower end of the non-bonded portion of the
polyethylene terephthalate film. The bonded assembly was suspended
in an atmosphere of 25.degree. C., whereby there was no slippage
observed at the bonded area one day later, with the bond being
cured.
Then, this tacky.adhesive agent was applied to a sheet of lauan
plywood (to a thickness of coating film of 100 .mu.), and the whole
applied surface was irradiated with light in the same manner as
described above, followed by sticking together with use of rollers
of a 0.5 mm thick melamine-resin sheet having warpage and curved
surface formed thereon. The bonded assembly, upon standing without
clamping at 25.degree. C. for 24 hours, showed no swelling between
the lauan plywood and decorative sheet, with excellent bonding.
Using birch lumber/birch lumber having 12 mm of thickness as
substrate and material to be bonded, with the same light
irradiation and curing conditions being employed, compressive shear
bonding strength, as measured at a compression rate of 5 mm/min
under the measuring conditions (23.degree. C. and humidity of 50%),
was found to be 110 kg/cm.sup.2, revealing complete material
breakdown (area of the bonded portion was 25 mm.times.25 mm=625
mm.sup.2).
Also, the mixed solution consisting of 50 parts of Resin Component
5 and 100 parts of Curing Agent 5 showed a pot life at 25.degree.
C. of 12 hours.
EXAMPLE 6
By mixing 100 parts of an acrylic polyol (with a weight average
molecular weight of 200,000 and an OH equivalent of 650) formed
from the vinyl polymerization of 60 parts of n-butyl acrylate, 20
parts of methyl methacrylate and 20 parts of hydroxyethyl
methacrylate, with 50 parts of n-butyl acrylate, 30 parts of
2-ethylhexyl acrylate, 35 parts of hydroxyethyl acrylate and 3
parts of methyl benzoylformate, there was prepared Curing Agent 6
(with an OH equivalent of 479).
20 parts of crude diphenylmethane diisocyanate was mixed with 100
parts of Curing Agent 6, and the mixture was applied on a sheet of
particle board (to a thickness of coating film of 100 .mu.). The
whole applied surface was irradiated with light under the same
conditions as described in Example 5, and a 0.6 mm thick decorative
sheet of natural wood having warpage and curved surface formed
thereon was adhered to the particle board by the use of rollers.
The bonded assembly, upon standing without clamping at 25.degree.
C. for 24 hours, showed excellent bonding, without swelling
produced between the particle board and decorative sheet.
REFERENCE EXAMPLE 1
The Resin Component 1 and Curing Agent 1 as used in Example 1 were
mixed, and the mixture was applied to an FRP surface having a
curved surface portion. A coronadischarge treated, 0.7 mm thick ABS
plate incorporated with fillers was adhered to the FRP substrate
using a roller, and the part susceptible to light irradiation under
the same light irradiation conditions as described in Example 1 was
irradiated with light. The assembly was allowed to stand without
clamping, with the result that the ABS plate got peeled off and did
not adhere to the FRP substrate.
* * * * *